该软件由两部分组成:MHA Manager(管理节点)和MHA Node(数据节点)。MHAManager可以单独部署在一台独立的机器上,管理多个master-slave集群;也可以部署在一台slave 节点上。MHA Node运行在每台MySQL服务器上,MHA_Manager会定时探测集群中的master 节点。当master 出现故障时,它可以自动将最新数据的slave提升为新的master,然后将所有其他的slave重新指向新的master。整个故障转移过程对应用程序完全透明。
在MHA自动故障切换过程中,MHA试图从宕机的主服务器上保存二进制日志,最大程度的保证数据的不丢失,但这并不总是可行的。例如,如果主服务器硬件故障或无法通过SSH访问,MHA 没法保存二进制日志,就会出现只进行故障转移但丢失了最新的数据的情况。使用MySQL5.5的半同步复制,可以大大降低数据丢失的风险。MHA可以与半同步复制结合起来。如果只有一个slave已经收到了最新的二进制日志,MHA可以将最新的二进制日志应用于其他所有的slave服务器上,因此可以保证所有节点的数据一致性。
目前MySQL已经成为市场上主流数据库之一,考虑到业务的重要性,MySQL 数据库单点问题已成为企业网站架构中大的隐患。随着技术的发展,MHA的出现就是解决MySQL单点的问题。另外随着企业数据量越来越庞大,数据库的压又成为企业的另一个瓶颈,MySQL多主多从架构的出现可以减轻MySQL本身的压力。这个实验主要阐述MHA的搭建和模拟MySQL 故障自动切换的过程。
实验思路:
MHA架构
1)数据库安装
2)一主两从
3)MHA搭建
故障模拟
1)主库失效
2)备选主库成为主库
3)从库2将备选主库指向为主库
主机 | 操作系统 | 主机名及地址 | 角色 |
---|---|---|---|
服务器 | CentOS7.6(64位) | manager/20.0.0.11 | 管理节点,安装manager组件和node组件 |
服务器 | CentOS7.6(64位) | Mysql1/20.0.0.12 | Master节点,安装node组件 |
服务器 | CentOS7.6(64位) | Mysql2/20.0.0.18 | Slave 节点,安装node组件 |
服务器 | CentOS7.6(64位) | Mysql3/20.0.0.19 | Slave节点,安装node组件 |
编译安装myaql数据库详细步骤连接
[root@localhost ~]# hostnamectl set-hostname mysql1
[root@mysql1 ~]# bash
[root@mysql1 ~]# vi /etc/hosts
20.0.0.12 mysql1
[root@mysql1 ~]# vi /etc/my.cnf
[mysqld]
……省略部分
server-id = 11
log-bin = master-bin
log-slave-updates = true
[root@mysql1 ~]# systemctl restart mysqld
[root@mysql1 ~]# ln -s /usr/local/mysql/bin/mysql /usr/sbin/
[root@mysql1 ~]# ln -s /usr/local/mysql/bin/mysqlbinlog /usr/sbin/
[root@mysql1 ~]# mysql -uroot -p
mysql> grant replication slave on *.* to 'myslave'@'20.0.0.%' identified by '123456';
mysql> grant all privileges on *.* to 'mha'@'20.0.0.%' identified by 'manager';
#######################下面这条授权最好也做一下,防止报错#####################
mysql>grant all privileges on *.* to 'mha'@'mysql1' identified by 'manager';
##########################################################################
mysql> flush privileges;
mysql> show master status;
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+-------------------------------+------------+---------------------+----------------------------+--------------------------+
| master-bin.000001 | 154 | | |
[root@localhost ~]# hostnamectl set-hostname mysql2
[root@mysql2 ~]# bash
[root@mysql2 ~]# vi /etc/hosts
20.0.0.18 mysql2
[root@mysql2 ~]# vi /etc/my.cnf
[mysqld]
……省略部分
server-id = 22
log-bin = master-bin //这条必须有,因为备选master需要有binlog日志文件
relay-log = relay-log-bin
relay-log-index = slave-relay-bin.index
[root@mysql2 ~]# mysql -uroot -p -e 'set global relay_log_purge=0'
[root@mysql2 ~]# systemctl restart mysqld
[root@mysql2 ~]# ln -s /usr/local/mysql/bin/mysql /usr/sbin/
[root@mysql2 ~]# ln -s /usr/local/mysql/bin/mysqlbinlog /usr/sbin/
[root@mysql2 ~]# mysql -uroot -p
mysql> grant replication slave on *.* to 'myslave'@'20.0.0.%' identified by '123456';
mysql> grant all privileges on *.* to 'mha'@'20.0.0.%' identified by 'manager';
#######################下面这条授权最好也做一下,防止报错#####################
mysql>grant all privileges on *.* to 'mha'@'mysql2' identified by 'manager';
##########################################################################
mysql> flush privileges;
mysql> change master to master_host='20.0.0.12',
-> master_user='myslave',
-> master_password='123456',
-> master_port=3306,
-> master_log_file='master-bin.000001',
-> master_log_pos=154;
[root@localhost ~]# hostnamectl set-hostname mysql2
[root@mysql1 ~]# bash
[root@mysql1 ~]# vi /etc/hosts
20.0.0.19 mysql3
[root@mysql1 ~]# vi /etc/my.cnf
[mysqld]
……省略部分
server-id = 33
no_master=1 //no_master表示这个节点不能作为master
relay-log = relay-log-bin
relay-log-index = slave-relay-bin.index
[root@mysql3 ~]# mysql -uroot -p -e 'set global relay_log_purge=0' //清除relay-log残存
[root@mysql3 ~]# systemctl restart mysqld
[root@mysql3 ~]# ln -s /usr/local/mysql/bin/mysql /usr/sbin/
[root@mysql3 ~]# ln -s /usr/local/mysql/bin/mysqlbinlog /usr/sbin/
[root@mysql1 ~]# mysql -uroot -p
mysql> grant replication slave on *.* to 'myslave'@'20.0.0.%' identified by '123456';
mysql> grant all privileges on *.* to 'mha'@'20.0.0.%' identified by 'manager';
#######################下面这条授权最好也做一下,防止报错#####################
mysql>grant all privileges on *.* to 'mha'@'mysql3' identified by 'manager';
##########################################################################
mysql> flush privileges;
mysql> change master to master_host='20.0.0.12',
-> master_user='myslave',
-> master_port=3306,
-> master_password='123456',
-> master_log_file='master-bin.000001',
-> master_log_pos=154;
mysql> create database 测试库;
Query OK, 1 row affected (0.01 sec)
mysql> show databases;
+--------------------+
| Database |
+--------------------+
| information_schema |
| 测试库 |
| mysql |
| performance_schema |
| sys |
| test |
+--------------------+
mysql> show databases; //同步成功
+--------------------+
| Database |
+--------------------+
| information_schema |
| 测试库 |
| mysql |
| performance_schema |
| sys |
| test |
+--------------------+
因为生产环境中mysql数据库是暴露在公网中的,因此需要密钥对认证
manager给mysql1和mysql2两台服务器(主和主备)公钥,免密登入
[root@localhost ~]# ssh-keygen -t rsa //一直回车就可以
[root@localhost ~]# ssh-copy-id 20.0.0.18
[root@localhost ~]# ssh-copy-id 20.0.0.12
mysql1给mysql2和mysql3发送公钥,后端服务器之间互相免密认证
[root@mysql1 ~]# ssh-keygen -t rsa //一直回车就可以
[root@mysql1 ~]# ssh-copy-id 20.0.0.18
[root@mysql1 ~]# ssh-copy-id 20.0.0.12
mysql2给mysql1和mysql3发送公钥,后端服务器之间互相免密认证
[root@mysql2 ~]# ssh-keygen -t rsa //一直回车就可以
[root@mysql2 ~]# ssh-copy-id 20.0.0.12
[root@mysql2 ~]# ssh-copy-id 20.0.0.19
mysql3给mysql2和mysql1发送公钥,后端服务器之间互相免密认证
[root@mysql3 ~]# ssh-keygen -t rsa //一直回车就可以
[root@mysql3 ~]# ssh-copy-id 20.0.0.18
[root@mysql3 ~]# ssh-copy-id 20.0.0.12
[root@localhost ~]# yum -y install ncurses-devel gcc-c++ perl-Module-Install
[root@localhost ~]# tar zxvf cmake-2.8.6.tar.gz -C /opt
[root@localhost ~]# cd /opt/cmake-2.8.6
[root@Mysql1 cmake-2.8.6]# ./configure
[root@Mysql1 cmake-2.8.6]# gmake -j3 && gmake install
[root@localhost ~]# yum install epel-release --nogpgcheck \
perl-DBD-MySQL \
perl-Config-Tiny \
perl-Log-Dispatch \
perl-Parallel-ForkManager \
perl-ExtUtils-CBuilder \
perl-ExtUtils-MakeMaker \
perl-Mail-Sender \
perl-CPAN
在<注意:所有服务器manager、mysql1、mysql2、mysql3>上必须先安装 node 组件,最后在 MHA-manager 节点上安装 manager 组件。因为 manager 依赖 node 组件,下面都是在 Mysql1 上操作演示安装 node 组件。
[root@localhost ~]# tar zxvf mha4mysql-node-0.57.tar.gz -C /opt
[root@localhost mha4mysql-node-0.57]# cd /opt/mha4mysql-node-0.57/
[root@localhost mha4mysql-node-0.57]# perl Makefile.PL
[root@localhost mha4mysql-node-0.57]# make && make install
[root@localhost mha4mysql-node-0.57]# ls /usr/local/bin
apply_diff_relay_logs filter_mysqlbinlog purge_relay_logs save_binary_logs
node 安装后也会在/usr/local/bin 下面会生成几个脚本(这些工具通常由 MHA_Manager 的脚本触发,无需人为操作)主要如下:
save_binary_logs | 保存和复制 master 的二进制日志 |
---|---|
apply_diff_relay_logs | 识别差异的中继日志事件并将其差异的事件应用于其他的 slave |
filter_mysqlbinlog | 去除不必要的 ROLLBACK 事件(MHA 已不再使用这个工具) |
purge_relay_logs | 清除中继日志(不会阻塞 SQL 线程) |
[root@localhost ~]# tar zxvf mha4mysql-manager-0.57.tar.gz -C /opt
[root@localhost ~]# cd /opt/mha4mysql-manager-0.57/
[root@localhost mha4mysql-manager-0.57]# perl Makefile.PL
[root@localhost mha4mysql-manager-0.57]# make && make install
[root@localhost mha4mysql-manager-0.57]# ls /usr/local/bin
masterha_check_repl masterha_check_status masterha_manager masterha_master_switch masterha_stop masterha_check_ssh
masterha_conf_host masterha_master_monitor masterha_secondary_check
manager 安装后在/usr/local/bin 下面会生成几个工具,主要包括以下几个:
工具 | 用途 |
---|---|
masterha_check_ssh | 检查 MHA 的 SSH 配置状况 |
masterha_check_repl | 检查 MySQL 复制状况 |
masterha_manger | 启动 manager的脚本 |
masterha_check_status | 检测当前 MHA 运行状态 |
masterha_master_monitor | 检测 master 是否宕机 |
masterha_master_switch | 控制故障转移(自动或者手动) |
masterha_conf_host | 添加或删除配置的 server 信息 |
masterha_stop | 关闭manager |
[root@localhost ~]# cp -ra /opt/mha4mysql-manager-0.57/samples/scripts/ /usr/local/bin/
[root@localhost ~]# ls /usr/local/bin/scripts/
master_ip_failover master_ip_online_change power_manager send_report
[root@localhost ~]# cp /usr/local/bin/scripts/master_ip_failover /usr/local/bin/
复制“master_ip_failover”脚本到/usr/local/bin 目录,这里使用脚本管理 VIP,也是推荐的一种方式,生产环境不建议使用 Keepalived。
脚本具体作用如下所示:
master_ip_failover | 自动切换时 VIP 管理的脚本 |
---|---|
master_ip_online_change | 在线切换时 vip 的管理 |
power_manager | 故障发生后关闭主机的脚本 |
send_report | 因故障切换后发送报警的脚本 |
直接复制即可用,ip等参数自行修改
#!/usr/bin/env perl
use strict;
use warnings FATAL => 'all';
use Getopt::Long;
my (
$command, $ssh_user, $orig_master_host, $orig_master_ip,
$orig_master_port, $new_master_host, $new_master_ip, $new_master_port
);
#############################添加内容部分#########################################
my $vip = '20.0.0.200';
my $brdc = '20.0.0.255';
my $ifdev = 'ens33';
my $key = '1';
my $ssh_start_vip = "/sbin/ifconfig ens33:$key $vip";
my $ssh_stop_vip = "/sbin/ifconfig ens33:$key down";
my $exit_code = 0;
#my $ssh_start_vip = "/usr/sbin/ip addr add $vip/24 brd $brdc dev $ifdev label $ifdev:$key;/usr/sbin/arping -q -A -c 1 -I $ifdev $vip;iptables -F;";
#my $ssh_stop_vip = "/usr/sbin/ip addr del $vip/24 dev $ifdev label $ifdev:$key";
##################################################################################
GetOptions(
'command=s' => \$command,
'ssh_user=s' => \$ssh_user,
'orig_master_host=s' => \$orig_master_host,
'orig_master_ip=s' => \$orig_master_ip,
'orig_master_port=i' => \$orig_master_port,
'new_master_host=s' => \$new_master_host,
'new_master_ip=s' => \$new_master_ip,
'new_master_port=i' => \$new_master_port,
);
exit &main();
sub main {
print "\n\nIN SCRIPT TEST====$ssh_stop_vip==$ssh_start_vip===\n\n";
if ( $command eq "stop" || $command eq "stopssh" ) {
my $exit_code = 1;
eval {
print "Disabling the VIP on old master: $orig_master_host \n";
&stop_vip();
$exit_code = 0;
};
if ($@) {
warn "Got Error: $@\n";
exit $exit_code;
}
exit $exit_code;
}
elsif ( $command eq "start" ) {
my $exit_code = 10;
eval {
print "Enabling the VIP - $vip on the new master - $new_master_host \n";
&start_vip();
$exit_code = 0;
};
if ($@) {
warn $@;
exit $exit_code;
}
exit $exit_code;
}
elsif ( $command eq "status" ) {
print "Checking the Status of the script.. OK \n";
exit 0;
}
else {
&usage();
exit 1;
}
}
sub start_vip() {
`ssh $ssh_user\@$new_master_host \" $ssh_start_vip \"`;
}
# A simple system call that disable the VIP on the old_master
sub stop_vip() {
`ssh $ssh_user\@$orig_master_host \" $ssh_stop_vip \"`;
}
sub usage {
print
"Usage: master_ip_failover --command=start|stop|stopssh|status --orig_master_host=host --orig_master_ip=ip --orig_master_port=port --new_master_host=host --new_master_ip=ip --new_master_port=port\n";
}
[root@localhost ~]# mkdir /etc/masterha //创建MHA软件存放目录
[root@localhost ~]# cp /opt/mha4mysql-manager-0.57/samples/conf/app1.cnf /etc/masterha
[root@localhost ~]# mkdir -p /var/log/masterha/app1
[root@localhost ~]# vi /etc/masterha/app1.cnf
[server default]
manager_log=/var/log/masterha/app1/manager.log //指定manager的日志文件
manager_workdir=/var/log/masterha/app1 //指定manager的工作目录
master_binlog_dir=/usr/local/mysql/data //master存放binlog的位置,要与master的存放位置一致
master_ip_failover_script=/usr/local/bin/master_ip_failover //设置自动failover时候的切换脚本位置
master_ip_online_change_script=/usr/local/bin/master_ip_online_change //设置手动切换时的切换脚本位置
user=mha //监控用户
password=manager //监控用户密码
ping_interval=1 //设置监控主库,发送ping包的时间间隔,默认是3秒,尝试三次没有回应的时候自动 进行failover故障切换
remote_workdir=/tmp //设置远端mysq|在发生切换时binlog的保存位置
repl_password=123456 //设置复制用户(从服务器用户)的密码
repl_user=myslave //设置复制用户(从服务器用户
secondary_check_script=/usr/local/bin/masterha_secondary_check -s 20.0.0.18 -s 20.0.0.19
shutdown_script="" //设置故障发生后关闭故障主机脚本(该脚本的主要作用是关闭主机防止发生脑裂)
ssh_user=root //使用ssh登录时的用户
report script=/usr/local/send_report //设置发生切换后发送的报警的脚本
[server1]
hostname=20.0.0.12
port=3306
[server2]
hostname=20.0.0.18
port=3306
candidate_master=1 ##候选master
check_repl_delay=0
[server3]
hostname=20.0.0.19
port=3306
##################################配置含义########################################
[root@localhost perl5]# masterha_check_ssh -conf=/etc/masterha/app1.cnf
Sat Sep 19 00:15:33 2020 - [warning] Global configuration file /etc/masterha_default.cnf not found. Skipping.
Sat Sep 19 00:15:33 2020 - [info] Reading application default configuration from /etc/masterha/app1.cnf..
……省略部分
Sat Sep 19 00:15:41 2020 - [info] All SSH connection tests passed successfully.
[root@localhost bin]# masterha_check_repl -conf=/etc/masterha/app1.cnf
Sat Sep 19 01:23:56 2020 - [warning] Global configuration file /etc/masterha_default.cnf not found. Skipping.
Sat Sep 19 01:23:56 2020 - [info] Reading application default configuration from /etc/masterha/app1.cnf..
Sat Sep 19 01:23:56 2020 - [info] Reading server configuration from /etc/masterha/app1.cnf..
Sat Sep 19 01:23:56 2020 - [info] MHA::MasterMonitor version 0.57.
Sat Sep 19 01:23:57 2020 - [info] GTID failover mode = 0
……省略部分
Sat Sep 19 01:24:36 2020 - [info] Checking replication health on 20.0.0.19..
Sat Sep 19 01:24:36 2020 - [info] ok.
Sat Sep 19 01:24:36 2020 - [info] Checking master_ip_failover_script status:
Sat Sep 19 01:24:36 2020 - [info] /usr/local/bin/master_ip_failover --command=status --ssh_user=root --orig_master_host=20.0.0.12 --orig_master_ip=20.0.0.12 --orig_master_port=3306
Sat Sep 19 01:24:36 2020 - [info] OK.
Sat Sep 19 01:24:36 2020 - [warning] shutdown_script is not defined.
Sat Sep 19 01:24:36 2020 - [info] Got exit code 0 (Not master dead).
MySQL Replication Health is OK.
[root@localhost ~]# nohup masterha_manager \ //启动MHA进程
--conf=/etc/masterha/app1.cnf \
--remove_dead_master_conf \
--ignore_last_failover \
< /dev/null > \
/var/log/masterha/app1/manager.log \
2>&1 &
[1] 18955
[root@localhost ~]# masterha_check_status --conf=/etc/masterha/app1.cnf app1
//查看master节点,即当前的master是那台主机
app1 (pid:18955) is running(0:PING_OK), master:20.0.0.12
[root@localhost ~]# cat /var/log/masterha/app1/manager.log
//通过日志也可以查看到当前master节点
……省略部分
Sat Sep 19 16:37:45 2020 - [info] Slaves settings check done.
Sat Sep 19 16:37:45 2020 - [info]
20.0.0.12(20.0.0.12:3306) (current master)
+--20.0.0.18(20.0.0.18:3306)
+--20.0.0.19(20.0.0.19:3306)
[root@localhost ~]# masterha_stop --conf=/etc/masterha/app1.cnf //关闭MHA
MHA Manager is not running on app1(2:NOT_RUNNING).
[root@localhost ~]# masterha_check_status --conf=/etc/masterha/app1.cnf app1
app1 (pid:19085) is running(0:PING_OK), master:20.0.0.12
[root@mysql~1 ifconfig ens33:1 20.0.0.100
[root@localhost ~]# ifconfig
ens33: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet 20.0.0.12 netmask 255.255.255.0 broadcast 20.0.0.255
inet6 fe80::b80f:265:a540:505 prefixlen 64 scopeid 0x20<link>
ether 00:0c:29:da:30:d2 txqueuelen 1000 (Ethernet)
RX packets 544 bytes 56176 (54.8 KiB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 371 bytes 52193 (50.9 KiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
ens33:1: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet 20.0.0.100 netmask 255.0.0.0 broadcast 20.255.255.255
ether 00:0c:29:da:30:d2 txqueuelen 1000 (Ethernet)
lo: flags=73<UP,LOOPBACK,RUNNING> mtu 65536
inet 127.0.0.1 netmask 255.0.0.0
inet6 ::1 prefixlen 128 scopeid 0x10<host>
loop txqueuelen 1000 (Local Loopback)
RX packets 224 bytes 24168 (23.6 KiB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 224 bytes 24168 (23.6 KiB)
[root@mysql1 data]# systemctl stop mysqld
[root@mysql]# ifconfig ##vip消失,发生了漂移
ens33: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet 20.0.0.18 netmask 255.255.255.0 broadcast 20.0.0.255
inet6 fe80::b80f:265:a540:505 prefixlen 64 scopeid 0x20<link>
ether 00:0c:29:da:30:d2 txqueuelen 1000 (Ethernet)
RX packets 544 bytes 56176 (54.8 KiB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 371 bytes 52193 (50.9 KiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
ens33:1: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet 20.0.0.100 netmask 255.0.0.0 broadcast 20.255.255.255
ether 00:0c:29:da:30:d2 txqueuelen 1000 (Ethernet)
lo: flags=73<UP,LOOPBACK,RUNNING> mtu 65536
inet 127.0.0.1 netmask 255.0.0.0
inet6 ::1 prefixlen 128 scopeid 0x10<host>
loop txqueuelen 1000 (Local Loopback)
RX packets 224 bytes 24168 (23.6 KiB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 224 bytes 24168 (23.6 KiB)
[root@localhost ~]# tail -f /var/log/masterha/app1/manager.log
……省略部分
Selected 20.0.0.18(20.0.0.18:3306) as a new master
Generating relay diff files from the latest slave succeeded.
20.0.0.19(20.0.0.19:3306): OK: Applying all logs succeeded. Slave started, replicating from 20.0.0.18(20.0.0.18:3306)
20.0.0.18(20.0.0.18:3306): Resetting slave info succeeded.
Master failover to 20.0.0.18(20.0.0.18:3306) completed successfully. // master已经转化成功
[root@mysql]# ifconfig ##vip地址到了mysql2
ens33: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet 20.0.0.12 netmask 255.255.255.0 broadcast 192.168.10.255
inet6 fe80::b80f:265:a540:505 prefixlen 64 scopeid 0x20<link>
ether 00:0c:29:da:30:d2 txqueuelen 1000 (Ethernet)
RX packets 544 bytes 56176 (54.8 KiB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 371 bytes 52193 (50.9 KiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
lo: flags=73<UP,LOOPBACK,RUNNING> mtu 65536
inet 127.0.0.1 netmask 255.0.0.0
inet6 ::1 prefixlen 128 scopeid 0x10<host>
loop txqueuelen 1000 (Local Loopback)
RX packets 224 bytes 24168 (23.6 KiB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 224 bytes 24168 (23.6 KiB)
mysql> CHANGE MASTER TO MASTER_HOST='20.0.0.18',
-> MASTER_PORT=3306,
-> MASTER_LOG_FILE='master-bin.000006',
-> MASTER_LOG_POS=154, MASTER_USER='myslave',
->MASTER_PASSWORD='123456';
mysql> start slave;
mysql> set global read_only=1;
mysql> stop slave;
mysql> reset slave;
将刚刚手动宕机 Mysql1 库作为主库继续提供服务,注意手动切换 VIP 不会漂移。重新检查数据库主从状态是否正常,修改后的 app1.cnf 文件内容如下
[root@localhost ~]# vi /etc/masterha/app1.cnf
[server default]
manager_log=/var/log/masterha/app1/manager.log
……省略部分
user=mha
[server1]
candidate_master=1
check_repl_delay=0
hostname=20.0.0.12
port=3306
[server2]
hostname=20.0.0.18
port=3306
[server3]
hostname=20.0.0.19
port=3306
最后启动 MHA 检查是否正常
[root@localhost ~]# nohup masterha_manager \ //启动MHA进程
--conf=/etc/masterha/app1.cnf \
--remove_dead_master_conf \
--ignore_last_failover \
< /dev/null > \
/var/log/masterha/app1/manager.log \
2>&1 &
[root@localhost ~]# masterha_check_status --conf=/etc/masterha/app1.cnf
app1 (pid:19335) is running(0:PING_OK), master:20.0.0.18
[root@localhost ~]# masterha_stop --conf=/etc/masterha/app1.cnf
Stopped app1 successfully.
[1]+ Exit 1
[root@localhost ~]# masterha_master_switch --conf=/etc/masterha/app1.cnf \
--master_state=dead \
--dead_master_host=20.0.0.18
[root@localhost ~]# masterha_check_status --conf=/etc/masterha/app1.cnf
app1 is stopped(2:NOT_RUNNING).
[root@localhost ~]# cp /usr/local/bin/scripts/master_ip_online_change /usr/local/bin/
[root@localhost ~]# vi /usr/local/bin/master_ip_online_change
……省略部分
151 print current_time_us() . " Drpping app user on the orig master..\n";
152 # FIXME_xxx_drop_app_user($orig_master_handler); //将这行注释掉
……省略部分
[root@localhost ~]# masterha_master_switch \
--conf=/etc/masterha/app1.cnf \
--master_state=alive \
--new_master_host=20.0.0.12 \
--orig_master_is_new_slave
……省略部分
Sun Sep 20 04:14:49 2020 - [info] 20.0.0.12: Resetting slave info succeeded.
Sun Sep 20 04:14:49 2020 - [info] Switching master to 20.0.0.12(20.0.0.12:3306) completed successfully. //提示切换成功
[root@localhost ~]# masterha_check_status --conf=/etc/masterha/app1.cnf
app1 monitoring program is now on initialization phase(10:INITIALIZING_MONITOR). Wait for a while and try checking again. //提示正在初始化,需要等待
[root@localhost ~]# masterha_check_status --conf=/etc/masterha/app1.cnf
app1 (pid:19517) is running(0:PING_OK), master:20.0.0.12 //大概等待2分钟,可以查看到master已经换成mysql1了
至此,MHA高可用集群部署完成
在从服务器上:
mysql -uroot -p -e ‘set global relay_log_purge=0’
在从服务器上:vi /etc/my.cnf
在[mysqld]参数下增加 log_bin=on
在从服务器上:vi /etc/my.cnf
在[client]参数下注释 #default-character-set=utf8
采用设置软连接的方式解决,三台 MySQL 上都需要执行
[root@Mysql1 ~]# ln -s /usr/local/mysql/bin/mysqlbinlog /usr/bin/mysqlbinlog
[root@Mysql1 ~]# ln -s /usr/local/mysql/bin/mysql /usr/bin/mysql
在 manager 机器上面使用如下解决方法。
[root@mha-manager ~]# vim /usr/local/bin/master_ip_failover
## Update master ip on the catalog database, etc
#FIXME_xxx; ###将此行注释